Air or gas filter unit



Q Ffib. 1936- H. E. BIRKHOLZ AIR OR GAS FILTER UNIT Filed March 27, 19332 Sheets-Sheet l INVENTOR. Hans E. Bii-KhoLz BY a W ATTORNEY P b. 4,1936. v H. E. BIRKHOLZ AIR OR GAS FILTER UNIT Filed March 27, 1933 2Sheets-Sheet 2 I N V EN TOR. Hcfns E Birkholz 4 A TTORNEY Patented Feb.4, 1936 PArsNroFF cs r ameon. GAS Hans E. Birkholz, Louisville, Ky.,assignor, to AmerlcanAir Filter Company, Inc., Louisville, Ky., acorporation of Delaware 1 Applicaflon hlarch 27, 1933, 'Serial No.662,931

4" cam. (01. 98-94)" This invention relates to an air or gasfilter unitof the type having a motor driven blower] and filter-medium mountedwithin a housing as '5 ticularlyintended for use adjacent the open win:

dow of a room wherein it functions tofili'lerthe air drawn through thewindow opening and to force it into the room.

An important o'bjectotthis invention'is to m'provide a, constructionoithis character, which permits the filter medium to be positioned suchthat while it is concealed from view and fully protected against thedestructiv'eaction or rain, snow, andotherelements encountered duringuse,

it neverthelessjremains instantly accessible. for

inspection and removal orreplacement.

Another object is to provide a construction by which the outside air maybe shut of! amine room air recirculated through the filter medium.

Another object isto' provide a constructionv having a removablechassison which the parts most subject toderangement are mountedwherebythey may be readily removed ior'repair or adjustment; 7 I g v 35 Afurther object is to accom lish the ioregoing objects with a "structureof extremely simple and f compact design, 7

The invention is illustrated injthe accompanying drawings wherein: VFigure 1 is a front perspective view of the casing with thelid (i raisedand the chassis, filter medium 1, screensupport 8, and guard member inremoved; t I

F re 21s a sectional view taken along line 85 2 2 of Figure 1 andshowing also therelation j of the casing with respect to a window as itappears inuse;

Figure 3 is a rear perspective view similar to Figure 1, but with the'filter medium 1, screen 40 support 8, and guard member 10 in place,these parts being suitably broken away. to bring out their relation;

Figure 4 is arfront perspective ofthechassis partly broken to show thesealing lip 20;

45 Figure 5 is a verticalseetiontaken through the chassis in aplanewhichpasses through the blower l 1 and to oneside of the nearest louvre l2.Figurelfi is a horizontal section through the filter unit with filtermedium etc. removed, the.

50 left half of this section being taken above the casing l4 and theright half centrally through' the unit.

Figure 7 is a sectional view taken along line |--'l of Figure 6 but withthe'filter medium in 55 place; and

[plates II and I3. a self-contained unit. "meconstruction 1 p31"-Incarrying out the invention I utilize a hous ing l, preierably composedoi sheet metal iash- 5 ioned in rectangular shape.- This housingcontains the working parts ofthe structure, and in use is positioned onthe sill S of a window W (see Figure 2 with its rear wall adjacent theopening of the window, the rear wall having a ledge 2 upon which thelower edge of the open window rests, A screen covered air inlet opening3 is providedin the rear wall of the housing under the ledge 2, thisopening preferably extendingthe length of the ledge. The inlet open- 5 fing 3 communicates with a rear vertical passage 4 which is defined bythe rear wall of the hous-' ing ,and'a partition {extending from therear bottom edge of the housing inwardly-tor a short distance and thenceupwardly to apolnt shortx of the top.. The air passing through thepassage 4 crosses over the upper edge of the partition 5 into the spacebetween the hinged lid 6 at the top of the housing and the filter medium1 (see Figures 3 and 7) and thence passes downwardly through the filtermedium 1. Any suitable filter medium may be utilized, At the presenttime I prefer the use of a paper medium such as is described and claimedin Patent No. 1,897,976, and consequently utilize a screen support 8therefor, thissupport preferably being held in the slanting positionshown by a seat 9 which is suitably formed on the 'upperparts of thepartition 5 and adjoining inner walls of the housing proper. If desiredthe paper may be held against the screen by an open guard member ID.with the filter medium in this position, it is not only effectivelyconcealed from view and protectedagainst the action of snow, rain, andother destructive agencies which may be contained in the outside 40 air,but, at the same time, it is through the agepcyof the lid 6 alwaysimmediately accessible for inspection, etc. Furthermore, the position ofthe lid and filter medium permit thelatter to be inspected in situ, theadvantage of which is obvious.

It will be noted that the partition 5 and filter medium 1 cooperatetodivide the housing into inlet and outlet chambers respectively, whichcommunicate with each other through the filter medium. The fan andblower mechanism are located in the outlet chamber and thereby protectedby the filter medium I against the action of the impurities carried bythe air being filtered. These parts may be mounted in any suitablemanner.

opening at its front, a filter medium extending from the upper portion0! the front wall rearwardly across the housing and dividing the entireinterior thereof into an upper inlet chamber and a lower outlet chamberwhich communicate respectively with said inlet and outlet openings, and

